I created a simple windows form application of OpenCV that captures stream of images from a webcam and detect the face and then display the image to a picture box. I created a separate thread to execute the face detector function. The form has a button and picture box and when the button is pressed, the face detector thread starts. It works fine for approximately 2 and half minutes and then it throws this exception:

"An unhandled exception of type 'System.Runtime.InteropServices.SEHException' occurred in Sampleapp.exe

Additional information: External component has thrown an exception."

Here is the entire code for the face detector function:

include "stdafx.h"

include "Form1.h"

include <cv.h>

include <highgui.h>

namespace Sampleapp {

using namespace System;
using namespace System::ComponentModel;
using namespace System::Collections;
using namespace System::Windows::Forms;
using namespace System::Data;
using namespace System::Drawing;

const char *frontalface_cascade_name = "haarcascade_frontalface_alt.xml";
CvHaarClassifierCascade *frontalface_cascade;
//----------------------
// Face detector
void Form1::face_detector()
{
    IplImage* img;
    IplImage *img_gray;
    CvMemStorage *storage;
    CvSeq* faces;
    /*CvSeq* righteye;
    CvSeq* lefteye;
    CvSeq* nose;*/
    frontalface_cascade = ( CvHaarClassifierCascade* )cvLoad( frontalface_cascade_name, 0, 0, 0 );
    while(this->button1->Text == "no")
    {
        try             
        {
            storage = cvCreateMemStorage( 0 );
            CvCapture *capture = cvCreateCameraCapture(0);
            img = cvQueryFrame(capture);
            img_gray = cvCreateImage( cvSize( img->width, img->height ), IPL_DEPTH_8U, 1 );
            cvCvtColor( img, img_gray, CV_BGR2GRAY );
            cvEqualizeHist( img_gray, img_gray );
            faces = cvHaarDetectObjects( img_gray, frontalface_cascade, storage, 1.1, 2, CV_HAAR_FIND_BIGGEST_OBJECT, cvSize(40, 40));
            this->pictureBox1->Image = (gcnew System::Drawing::Bitmap(img->width,img->height,img->widthStep, System::Drawing::Imaging::PixelFormat::Format24bppRgb,(System::IntPtr)img->imageData));                            
            cvReleaseMemStorage(&storage);
        }
        catch (System::NullReferenceException^ m)
        {
        }
    }
}

}

The exception is thrown at: faces = cvHaarDetectObjects( .....) segment.

If anyone has any idea what I should to solve this problem, please let me know.

Sincerely,

I created a simple windows form application of OpenCV that captures stream of images from a webcam and detect the face and then display the image to a picture box. I created a separate thread to execute the face detector function. The form has a button and picture box and when the button is pressed, the face detector thread starts. It works fine for approximately 2 and half minutes and then it throws this exception:

"An unhandled exception of type 'System.Runtime.InteropServices.SEHException' occurred in Sampleapp.exe

Additional information: External component has thrown an exception."

Here is the entire code for the face detector function:

#include "stdafx.h"
#include "Form1.h"
#include <cv.h>
#include <highgui.h>

namespace Sampleapp {
 
{

    using namespace System;
 using namespace System::ComponentModel;
 using namespace System::Collections;
 using namespace System::Windows::Forms;
 using namespace System::Data;
 using namespace System::Drawing;

 const char *frontalface_cascade_name = "haarcascade_frontalface_alt.xml";
 CvHaarClassifierCascade *frontalface_cascade;
 //----------------------
 // Face detector
 void Form1::face_detector()
 {
     IplImage* img;
     IplImage *img_gray;
     CvMemStorage *storage;
     CvSeq* faces;
     /*CvSeq* righteye;
     CvSeq* lefteye;
     CvSeq* nose;*/
     frontalface_cascade = ( CvHaarClassifierCascade* )cvLoad( frontalface_cascade_name, 0, 0, 0 );
     while(this->button1->Text == "no")
     {
         try             
         {
             storage = cvCreateMemStorage( 0 );
             CvCapture *capture = cvCreateCameraCapture(0);
             img = cvQueryFrame(capture);
             img_gray = cvCreateImage( cvSize( img->width, img->height ), IPL_DEPTH_8U, 1 );
             cvCvtColor( img, img_gray, CV_BGR2GRAY );
             cvEqualizeHist( img_gray, img_gray );
             faces = cvHaarDetectObjects( img_gray, frontalface_cascade, storage, 1.1, 2, CV_HAAR_FIND_BIGGEST_OBJECT, cvSize(40, 40));
             this->pictureBox1->Image = (gcnew System::Drawing::Bitmap(img->width,img->height,img->widthStep, System::Drawing::Imaging::PixelFormat::Format24bppRgb,(System::IntPtr)img->imageData));                            
             cvReleaseMemStorage(&storage);
         }
         catch (System::NullReferenceException^ m)
         {
         }
     }
 }
}
 
} 
The exception is thrown at: 
faces = cvHaarDetectObjects( .....) .....)
 segment.
 
If anyone has any idea what I should to solve this problem, please let me know.
 
Sincerely, Josiah